Originally Posted by
Afro Thunda
In my opinion, Ichigo should never, ever reach this pinnacle of power ever again, nor should there be an enemy that reaches a power on the same level as Aizen requiring Ichigo to achieve that power again. Unless, of course, he ends up fighting Aizen again.
I would like to think it cosmetic the same way the change, albeit drastic, between Zangetsu and Tensa Zangetsu is largely cosmetic.
I'd like to think it's a combination of both, but it's more likely that the addition of his Full-Bring abilities changed the appearance of his zanpakuto. I mean, there wouldn't really be any reason for the change if all he was getting was a huge portion of reiatsu poured into him to fully reawaken his Shinigami powers. At least that's how I see it.